Update infotype 0014 based on entries in infotype 0008

Hello Experts,

We are storing only basic salary in infotype 0008.There are few allowances which are derived from basic salary amount but are to be stored in infotype 0014. Is there any way to achieve this?

Example:

Maintain or Change Basic Salary in infotype 0008, automatically system should update dependent allowances in infotype 0014 (in the background).

Dynamic action can not be a solution to this for two reasons:

1.They are not called when you do mass upload through BDC or LSMW.

2.We also have ECM in scope, hence every year when the ECM module will update the basic salary (Through standard program), the dynamic action will not update the dependent allowances.

Thanks